Valve for steam-engines.



L. R. BAKER.

VALVE FOR STEAM ENGINES.

APPLICATION FILED APR. 6. 191a.

Z SHEETS-SHEET 1.

Patehted Dec. 10, 1918.

L. R. BAKER.

' \(AL VE FOR STEAM ENGINES.

APPLICATION FILED APR. 6. 1918.

Patented Dec. 10, 1918.

- 2 SHEETSSHEET 2. 4 a

LOUIS RALPH BAKER, or swnn'ron, OHIO.

- VALVE FOR STEAM-ENGINES.

Specification of Letters Patent.

Patented Dec. 10, 1918.

Application filed April 6, 1918. Serial No. 226,998..

To all whom it may concern:

Be it known that I, LOUIS R. BAKER, a

citizen of the United States, residing at Swanton, in the county ofFulton and State of Ohio, have invented certain new and usefulImprovements in Valves for Steam- Engines; and I do declare thefollowing to be a full, clear, and exact description of the invention,such as will enable, others skilled in the art to which it appertains tomake and use the same, reference being had to the accompanying drawings,and to the letters and figures of reference marked thereon, which form2. art of this specification.

My invention r ates to the valve and port construction of reciprocatingsteam engines of the uniflow and counterflow types, and is designed toprovide simple and efiicient means for maintaining low compression onthe exhaust side of the engine-piston, and for securing as late arelease or exhaust as may be required regardless of the point of cut 03.

To these ends my vention consists of the devices, construction andarrangement of parts fully described in the following specification, andwhile, in its broader aspect, it is capable of embodiment in numerousforms, certain preferred illustrative embodiments thereof are shown inthe accompanying drawings, in which- Figure 1 1s a lon 'tudinal centralsectional View of the mam cylinder and yalvecylinder of a reciprocatingsteam englne of the unifiow type, together with the steamchest, theengine-piston, the valves and the several passages and ports hereinafterreferred to; Fig. 2, a central longitudinal section of myvalve-mechanism in a modified form, as applied to a counterfiow engine;Fig. 3 a like view of an engine of the counterflow slide valve type, inwhich is embodied a modified form of slide valve and port constructionin accordance with my invention, and Fig. 4:, an indicator-card takenfrom my engine, illustrated in Fig. 1.

Like letters and numerals indicate like parts throughout the drawings.

In the drawings, referring to Fig. 1, A designates. the main enginecylinder in which reciprocates a piston B, having a pis ton-rod C. Thepiston is a hollow cylinder of half the length of the chamber of themain cylinder, minus the horizontal midth of ports, a series of whichlead from such chamber midway of its length, and the stroke of thepiston is equal to its own length plus the width of such ports. D is avalve-cylinder secured in operative relation to the main cylinder A,also to a steamchest E, which has a steam -supply through suitableconnections, not shown. The steamchest, through openings 6, is inuninterrupted communication with both ends of the chamber of the valvecylinder D. In the valve-cylinder reciprocates a valve-rod F, which isactuated in harmony with the movement of the piston B by the usual orany preferred connecting mechanisms.

pon the valve-rod F are secured three piston-valves 123. Theintermediate valve-piston 3 has therethrough openings parallel with thevalve-rod. These valves respectively work in an internal sleeve orbushing in the valve-cylinder, in which bushings are ports in, operativerelation to the valves. These ports open into annular passages, formedin annular ribs 03, integral with the wall of the valve-cylinder. Theports governed by the respective valves are correspondingly designatedas 1, 2 and 3 and the steam passages with which the ports communicate as1" and 2". controlled by valve 1, leads into one end of thepiston-chamber A. The passage 2 controlled by the valve 2, leads intothe op-,'

posite end of said chamber. The port con trolled by valve 3 leads intoan annular exhaust passage 4, formed in the wall of the cylinder A,which passage is in communication with the chamber of the cylinder Athrough a series of ports 5. formed in the wall of the cylinder midwayof its length.

The interior of the valve-cylinder between the valves 1 and 2 may beregarded as a single chamber 6, since both ends of this space are incommunication through the openings through the valve 3. Fixed upon thevalve-rod F are hollow closed displacement members 7, which, for thepurpose hereinafter explained, reduces the space between the valves 1and 2 to predetermined proportions.

The operation of my device, as illustrated in Fig. 1, may be bestexplained by following the movement of the main piston and the valvesthrough one stroke of the engine. 1

The engine is on dead center. The exhaust is taking place through ports,2, 3 and 5, which are open. The valve-rod F is moving to the right, andvalve 1 is begin- The passage 1 -of stroke, f, valve 3covers ning to uncver the port 1*. This movepleted its stroke and has traveled'substantially one-half of its return stroke. The greater volume ofexhaust steam having been released, port? is now closed in advance ofport 2" permitting the remaining exhaust steam to be compressed throughport 2 into the chamber 6 between the valves 1 and 2, thus building upthe pressure in the chamber 6. Just before valve 1 opens the port 1*, asit passes to the left, the. pressure in the chamber 6 is the same as inthe cylinder. When the port 1 'is'opened to chamber 6 the steam on theleft hand side of the piston would be released,as indicated by thedotted line 0@ in the indicator card, Fig. 4,-were it not for thepressure built up in the chamber 6 and retained there by valve 3 and bythe compression on the opposite side of the piston. The advancing pistonearly ports 5. Thesein its stroke has closed the ports are uncovered atthe end of the stroke of the. piston at about the same time the ports 3are uncovered by the further movement to the left of the valve 3. Thus,until near the end of the stroke, compression is negligible and a laterelease is obtained. It

.willbe seen that were it not for valve 3 and ports 3 compression wouldbegin as soon as the. engine piston had closed the ports 5, and that theeffect would be as indicated by the dotted line aaa on the indicatorcard, Fig.

.4. It will be understood that the return stroke of the piston with arepetition, in re verse, of the indicator card is obtained by an exactreversal of the valve movement above described,

The pressure in the chamber 6 is varied and controlled by the size ofthe displacement-members 7.

Inthe indicator card a indicates admission, b cut ofi', c chamber 6opened to port 1, d release at 5 and 3, e end port 3*, and fwcompression line.

If the expansion line on the indicatorcardfdr'ops when the valve 1 or 2opens to release, larger displacement members must be substituted to cutdown clearance space and to increase the-pressure in the chamber.

The release of the exhaust is continuous until the valve-rod has com---the width of said ports,

and 2, and, as. will be seen-without further explanation, theintermediate valve 3 is designed to close its port in advance of theclosing of either of the ports 1 8 against complete exhaust, thecompression thus produced is admitted to the expansion side of thepiston and compression is thereby reduced and a-late release isobtained.

Having described my! invention, what I claim and desire to secure byLetters Pat1 ent is 1. In a valve-mechanism for steam engines, anengine-cylinder, a reciprocating piston therein, a valve-casingconnected at each end with a steam supply and having near each endanadmimion and exhaust port in communication with the corresponding end ofthe chamber of the engine-cylinder, having also, midway of its length,an exhaust port leading to an exhaust passage in communication with eachof said ports, for each of said three ports a valve the spaces betweenthe middle and end valves being in communication through an opening inthe middle valve,-and a valve-rod adapted to actuate said three'valvesin harmony with the movement of the piston.

2. In a steam engine, a valve-casing adapted for connection at each endwith a steam supply and having near each end a port for admission andexhaust, having, also, midway between its'ends, an exhaust port, foreach of said ports a valve, and a valve-rod operatively connected withsaid three valves, said intermediate valve being arranged to close itsport in advance of the closlng of either of the saidend-ports againstexhaust,

the spaces between the intermediate 'valve and the end valves being inconstant bommunication.

3. In a steam engine, having at each end of its for the admission andexhaust of steam, having, also, midway between its ends, an annularseries of ports in communication with an annular exhaust passage in thewall of said cylinder, in. the cylinder a piston having a stf'okeequalto its own lengthplus a valve-casing n operative relation tothe'engine-cylinder and having at each end steam inlet connections,having also, near each end, ports in communication with thecorresponding passage at the end of the engine-cylinder, having also,midway of its length, ports leading into said annular exhaust passage,three valves which control the end. and middle ports last mentioned, anda valve-rod for said three Valves, the' intermediate valve beingarranged to close its port in advance of the closing of either of'saidexhaust, the spaces between the intermediate valve and the end valvesbeing in constant communication.

4. In a'steam engine, an engine cylinder,

end ports against a piston therein, a valve-casing adapted at both endsfor connection with a steam supply and having near each end a port foradmission to and exhaust from the engine, having also, midway of itslength, an exhaust-port, an exhaust passage in communication with saidseveral ports, a valve for .each of said ports, and a valve-rod commonto said valves, the arrangement being such that the intermediate valveis closed against exhaust in advance of the closing against exhaust ofthe end valve on the exhaust side of the piston, whereby compressiontakes place in the valve-chamber near the end of the stroke of thepiston and such that by the movementof the end valve on the expansionside of the piston such compression is admitted to the expansion side ofthe piston.

5. In a steam engine, an engine cylinder, a piston therein, avalve-casing adapted at both ends for connection with a steam supply andhaving near each end a port for admission to and exhaust from theengine,

having also, midway of its length, an exhaust-port, an exhaust passageincommumcation with said several ports, a valve for each of said ports,a valve-rod common to said valves, the arrangement being such that theintermediate valve is closed against exhaust-in advance of the closingagainst exhaust of the end valve on the exhaust side of the piston,whereby compression takes place in the valve-chamber near the end of thestroke of the piston, and such that by the movement of the end valve onthe expansion side of the piston such compression is admitted to theexpansion side of the piston, and, in the space between said end valves,displacement devices adapted by their size to control the extent of suchcompression.

In testimony whereof I afiix my signature in presence of two witnesses.

LOUIS RALPH BAKER.

Witnesses SAMUEL ZIMMERMAN, HILDA RETHINGER.

